Vehicle seat back

Abstract

To provide a vehicular seat back which inhibits change of an attitude of an occupant during turning without deteriorating the ride quality.SOLUTION: A vehicular seat back 11 includes a pad 3 and a pressure receiving member 4. The pad has: a foam member 31 which elastically deforms; and a reinforcement member 32 which is applied to a rear surface of the foam member and reinforces the foam member. The pressure receiving member has: a base part 69 located at a center part as seen in a width direction of the seat back; and multiple side pieces 60 which respectively extend outward in the width direction from both sides of the base part. The pad has reinforcement reduction parts 321 which weaken reinforcement of the reinforcement member at positions which overlap with parts of the side pieces when viewed from a direction orthogonal to a surface of the seat back.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The technology disclosed herein relates to a vehicle seat back. [Background technology]

[0002] Patent Document 1 describes a vehicle seat back. The seat back includes a seat back frame, a cushion pad, and a pressure-receiving member. The pressure-receiving member is a resin plate. The pressure-receiving member is located behind the cushion pad and attached to the seat back frame via a wire. The wire is molded integrally with the pressure-receiving member by insert molding. The pressure-receiving member receives a load from the back of the occupant. Furthermore, when an impact load from the back of the occupant is input to the pressure-receiving member during a rear-end collision of the vehicle, the pressure-receiving member is pushed by the back of the occupant and moves rearward together with the occupant. The displacement of the pressure-receiving member reduces the impact load acting on the occupant's neck during a collision.

[0003] Patent Document 2 also describes a vehicle seat back equipped with a plate-shaped pressure-receiving member. The pressure-receiving member can be swung by an actuator. When a turning sensor detects a vehicle turning, the actuator swings the pressure-receiving member in accordance with the turning direction. The swung pressure-receiving member can tilt the driver's posture inward relative to the turning direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-182273 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-49356 Summary of the Invention [Problem to be solved by the invention]

[0005] When a vehicle turns, the posture of an occupant seated in a seat tends to change. Vehicle seats are required to suppress changes in the occupant's posture. However, if a vehicle seat rigidly holds the occupant's posture, it will deteriorate the ride comfort when the vehicle is traveling straight. Furthermore, holding the occupant's posture rigidly will increase the reaction force from the seat back against changes in the occupant's posture when turning, making the occupant feel uncomfortable.

[0006] Unfortunately, the conventional vehicle seat described in Patent Document 1 cannot solve this problem. In addition, the conventional vehicle seat described in Patent Document 2 is very complicated because it requires electrical devices such as actuators and sensors.

[0007] The technology disclosed herein suppresses changes in the posture of the occupant when cornering without deteriorating the ride comfort. [Means for solving the problem]

[0008] The technology disclosed herein relates to a vehicle seat back. A pad that supports the occupant's back, a pressure-receiving member located behind the pad and receiving a load from the back of the occupant via the pad, The pad includes an elastically deformable foam member and a reinforcing member attached to a rear surface of the foam member and reinforcing the foam member, The pressure-receiving member has a base portion located at a center portion in a width direction of the seat back, and a plurality of side pieces extending outward in the width direction from both sides of the base portion, The pad has a reinforcement reducing portion that reduces the reinforcement of the reinforcing member at a position that overlaps with a part of the side piece when viewed in a direction perpendicular to the surface of the seat back.

[0009] According to this configuration, the base of the pressure-receiving member is located in the center in the width direction and supports the center of the occupant's back, and the side pieces of the pressure-receiving member are located on either side of the base and support either side of the occupant's back.

[0010] When the vehicle is traveling straight, the pressure-receiving member receives the load from the entire back of the occupant via the pad. The pad has a foam member and a reinforcing member. The load from the back of the occupant is received mainly by the base of the pressure-receiving member as the foam member reinforced by the reinforcing member undergoes compressive deformation. The pad and pressure-receiving member receive the load from the back of the occupant over their entire wide surfaces. Therefore, when the vehicle is traveling straight, the seat back can firmly support the back of the occupant without compromising ride comfort.

[0011] When a vehicle turns, the occupant's posture tends to change in a direction that causes the thorax to rotate around the spine and / or tilt left or right. As the occupant's posture changes, a load is input locally from the side of the occupant's back to the seat back.

[0012] Here, the term "occupants" includes both the driver who sits in the driver's seat and holds the steering wheel, and the passenger who sits in the front passenger seat. The change in the driver's posture when the vehicle turns may not coincide with the change in the passenger's posture when the vehicle turns.

[0013] The pad has a reinforcement lowered portion. The reinforcement lowered portion is located at a position overlapping with a part of the side piece. A local load from the side of the occupant's back is input to the position of the reinforcement lowered portion in the pad.

[0014] The reinforcement reduced portion reduces the reinforcement of the reinforcing member. At the initial stage of the local load input, the foam member undergoes significant compressive deformation at the reinforcement reduced portion. At the initial stage of the local load input, a strong reaction force is prevented from acting on the occupant.

[0015] After the foam member is compressed and deformed, the local load from the side of the occupant's back is received mainly by the side pieces of the pressure-receiving member. Then, a reaction force acts on the side of the occupant's back from the pressure-receiving member through the pad, thereby suppressing changes in the occupant's posture.

[0016] The seat back having the above-described configuration can firmly support the back of the occupant and suppress changes in posture while suppressing strong reaction forces acting on the occupant when the vehicle turns.

[0017] On the other hand, the reinforcement lowering portion is provided only at a specific location on the pad. When a load is input to the seat back from the entire back of the occupant, such as when the vehicle is traveling straight, the reinforcement lowering portion does not substantially function. A seat back with the above configuration does not deteriorate the ride comfort when the vehicle is traveling straight.

[0018] Therefore, the seat back having the above configuration can suppress changes in the posture of the occupant when turning without deteriorating the riding comfort when traveling straight or when turning.

[0019] The reinforcing lowered portions may be located on both sides of the center line of the seat back in the width direction.

[0020] The reinforcement lowering portions are located on both the right and left sides of the back of the occupant, and the seat back can suppress changes in the occupant's posture when turning right and when turning left.

[0021] The plurality of side pieces are provided on both sides of the base. ,above They are spaced apart downwards, The reinforcing lowered portion overlaps with the specific side piece on each side of the base portion, The particular side piece may have higher rigidity than the side piece adjacent to the particular side piece.

[0022] The high-rigidity side pieces can provide sufficient reaction force to the sides of the occupant's back, so that the seat back can suppress changes in the occupant's posture when the vehicle turns.

[0023] The reinforcement depression may be located behind the thorax of the occupant.

[0024] When a vehicle turns, the thorax tends to rotate around the spine and / or tilt left and right. By positioning the reinforcement lowering portion behind the occupant's thorax, the side pieces of the pressure-receiving member can apply a reaction force to the thorax, which tends to displace. The seat back can effectively suppress changes in the occupant's posture when the vehicle turns.

[0025] The side pieces may extend forward and outward in the width direction from the base portion.

[0026] The side pieces extending diagonally forward from the base can apply a reaction force to the areas from the sides of the occupant's back to the sides of the occupant's body. The seat back can effectively suppress changes in the occupant's posture in the direction of rotation of the thorax and / or in the direction of tilting the thorax to the left or right.

[0027] the reinforcing member is a nonwoven fabric, The reinforcement reduced portion may be a notch or a slit formed in the nonwoven fabric.

[0028] The nonwoven fabric attached to the rear surface of the foam member controls the amount of compression of the foam member, allowing the seat back to properly support the occupant's back and improve riding comfort. The notches or slits formed in the nonwoven fabric do not constrain the rear surface of the foam member, reducing the reaction force when a load is input from the occupant's back. As a result, the seat back initially reduces the reaction force on the occupant's back in response to localized load input when the vehicle turns, and then, mainly through the side pieces of the pressure-receiving member, applies sufficient reaction force to the sides of the occupant's back, thereby suppressing changes in the occupant's posture.

[0029] The vehicle seat back may further include an airbag for seat ventilation located between the pad and the pressure-receiving member.

[0030] The airbag prevents direct contact between the pad and the pressure-receiving member, including the area of ​​the reinforcement lowered portion, thereby reducing wear and / or damage to the foam member. [Effects of the Invention]

[0031] As described above, the vehicle seat back can suppress changes in the posture of the occupant when turning without deteriorating the riding comfort. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 shows a vehicle seat. [Figure 2] Figure 2 shows the inside of the seat back as seen from the front. [Figure 3] FIG. 3 shows the inside of the seat back as seen from the side. [Figure 4] Figure 4 shows the inside of the seat back as seen from the rear. [Figure 5] FIG. 5 shows the pressure-receiving member as seen from the front. [Figure 6] The left diagram in FIG. 6 shows the pressure-receiving member as seen from the side, and the right diagram shows the pressure-receiving member as seen from the rear. [Figure 7] FIG. 7 shows the VII-VII end face of FIG. [Figure 8] FIG. 8 shows the rear side of the pad. [Figure 9] FIG. 9 shows a modified rear surface of the pad. DETAILED DESCRIPTION OF THE INVENTION

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle seat back will be described with reference to the drawings. The seat back described here is an example.

[0034] (Overall seat back structure) The vehicle seat 1 is installed in the vehicle cabin as a front seat. In the following description, the front, rear, left, right, and top and bottom of the vehicle seat 1 correspond to the front, rear, left, right, and top and bottom of the vehicle when the vehicle seat 1 is installed in the vehicle cabin. The left-right direction corresponds to the width direction of the vehicle seat.

[0035] As shown in FIG. 1, the vehicle seat 1 includes a seat back 11, a seat cushion 12, and a headrest 13. The seat back 11 supports the back of an occupant 9 (see also FIG. 3). The seat cushion 12 supports the buttocks of the occupant 9. The headrest 13 supports the head of the occupant 9.

[0036] As shown in FIGS. 2 to 4 and 6, the seat back 11 includes a frame 2, a pad 3, a cover 30, and a pressure-receiving member 4. As shown in FIGS.

[0037] The frame 2 has left and right side frames 21, an upper frame 22, and a lower frame 23. The upper frame 22 connects the upper ends of the left and right side frames 21 together in the left-right direction. The lower frame 23 connects the lower ends of the left and right side frames 21 together in the left-right direction. The frame 2 is a substantially rectangular frame when viewed from the front.

[0038] The pad 3 is located in front of the frame 2. As shown in the left diagram of FIG. 6, the pad 3 is made up of a foam member 31 and a reinforcing member 32 attached to the rear surface of the foam member 31. The foam member 31 is a cushion member made of, for example, urethane foam. The reinforcing member 32 is made of, for example, nonwoven fabric. The reinforcing member 32 reinforces the rear surface of the foam member 31. The foam member 31 reinforced by the reinforcing member 32 elastically deforms when subjected to a load from the back of the occupant 9, and applies an appropriate reaction force to the back of the occupant 9.

[0039] The cover 30 is substantially bag-shaped and covers the entire seat back 11. As will be described later, the vehicle seat 1 is equipped with seat ventilation 5. The cover 30 is made of a breathable material, such as fabric, or natural leather or synthetic leather with numerous small holes.

[0040] The pressure-receiving member 4 is located inside the frame 2 and behind the pad 3. The pressure-receiving member 4 receives the load from the back of the occupant 9 via the pad 3. The pressure-receiving member 4 will be described in detail later.

[0041] As shown in the left diagram of FIG. 6, an airbag 51 of the seat ventilation 5 is positioned between the pad 3 and the pressure-receiving member 4. The airbag 51 prevents the rear surface of the pad 3 from directly contacting the pressure-receiving member 4. The airbag 51 suppresses wear and / or damage to the pad 3.

[0042] The seat ventilation 5 draws the air in the vehicle compartment, which has been conditioned by the air conditioner, into the seat back 11 through the surface of the seat back 11. The seat ventilation 5 has an airbag 51 and a fan 52.

[0043] As shown in the left diagram of Fig. 6 or Fig. 8, the foam member 31 has a plurality of through holes 311. Each through hole 311 penetrates from the front surface to the rear surface of the foam member 31. As described above, the skin 30 is made of a breathable material.

[0044] As shown in FIGS. 2 to 4, the fan 52 is located inside the frame 2 and above the pressure-receiving member 4. The fan 52 has an intake port 521 on its front surface. The fan 52 has an exhaust port 522 on each of its left and right side surfaces. The two exhaust ports 522 open to the inside of the seat back 11.

[0045] The suction port 521 is connected to the rear surface of the airbag 51. Although not shown in detail in the drawings, openings that are connected to the through holes 311 of the foam member 31 are formed in the front surface of the airbag 51.

[0046] When the fan 52 is activated, air in the vehicle cabin is drawn into the airbag 51 through the skin 30 and the through-holes 311. The airbag 51 functions as a manifold that collects the air drawn in through the through-holes 311. The fan 52 draws air into the airbag 51 through the intake port 521 and discharges it from the exhaust port 522.

[0047] (Structure of pressure-receiving member) The pressure-receiving member 4 has a main body 6 and a rigid member 7 .

[0048] The main body 6 has a base 69 and a plurality of side pieces 60. The main body 6 is in the form of a plate that is thin in the front-rear direction, and is made of, for example, synthetic resin.

[0049] The base 69 is located at the center in the width direction of the seat back 11. The base 69 has a generally rectangular shape when viewed from the front and extends in the vertical and horizontal directions. A plurality of holes are formed in the base 69 to reduce weight.

[0050] The upper end of the base 69 is located at a position corresponding to the lower part of the thorax 91 of the occupant 9 (see also FIG. 5). The lower end of the base 69 is located at a position corresponding to the waist of the occupant 9. The base 69 supports the center of the back of the occupant 9 in the left-right direction, between the position corresponding to the lower part of the thorax 91 of the occupant 9 and the position corresponding to the waist. The thorax 91 includes the clavicles, sternum, ribs, and thoracic vertebrae of the human body.

[0051] The side pieces 60 extend outward in the width direction from both left and right side edges of the base 69. More specifically, when viewed from the front, the side pieces 60 extend outward in the width direction from the side edges of the base 69 (see the right diagram in FIG. 5 or FIG. 6), and when viewed from the side, they extend further forward than the base 69 (see the left diagram in FIG. 6). The side pieces 60 are inclined forward relative to the base 69.

[0052] The multiple side pieces 60 are lined up at intervals in the vertical direction. The main body 6 has, from top to bottom, a first side piece 61, a second side piece 62, a third side piece 63, a fourth side piece 64, a fifth side piece 65, a sixth side piece 66, and a seventh side piece 67. Each of the first side piece 61 to the seventh side piece 67 has the same shape on the left and right.

[0053] The first side piece 61 is located at the upper end of the base 69. The first side piece 61 has the shortest length in the left-right direction. The first side piece 61 has higher rigidity than the adjacent second side piece 62. The first side piece 61 is formed with a first hole 611 for weight reduction and / or rigidity adjustment.

[0054] The second side piece 62 is located below the first side piece 61. The second side piece 62 to the seventh side piece 67 have approximately the same length. The second side piece 62 has two second holes 621 formed therein for weight reduction and / or rigidity adjustment.

[0055] The third side piece 63 is located below the second side piece 62. The third side piece 63 is formed with a third hole 631 for weight reduction and / or rigidity adjustment.

[0056] The fourth side piece 64 is located below the third side piece 63. A first recess 641 is formed in the fourth side piece 64 to improve rigidity. The first recess 614 is recessed from the front to the rear of the fourth side piece 64 (see the left diagram in Figure 6). A protrusion is formed on the rear surface of the fourth side piece 64.

[0057] The fifth side piece 65 is located below the fourth side piece 64. Similar to the fourth side piece 64, the fifth side piece 65 also has a second recess 651 formed therein to improve rigidity.

[0058] The sixth side piece 66 is located below the fifth side piece 65. Similar to the fourth side piece 64, the sixth side piece 66 also has a third recess 661 formed therein for improving rigidity. The seventh side piece 67 is located below the sixth side piece 66. Similar to the fourth side piece 64, the seventh side piece 67 also has a fourth recess 671 formed therein for improving rigidity. The tip of the sixth side piece 66 and the tip of the seventh side piece 67 are connected to each other in the vertical direction.

[0059] The rigid member 7 is located on the rear side of the main body 6. The rigid member 7 is fixed to the rear surface of the main body 6. More specifically, a fixing portion 68 that bulges upward from a base 69 is formed at the upper end of the main body 6. The fixing portion 68 is located above the first side piece 61. The main body 6 has two fixing portions 68. The two fixing portions 68 are located at the center of the main body 6 in the left-right direction, with a gap between them in the left-right direction. The rigid member 7 is fixed to the rear surfaces of the two fixing portions 68, respectively.

[0060] The rigid member 7 is made of, for example, synthetic resin. The rigid member 7 is thicker in the front-to-rear direction than the plate-shaped main body 6 (see also Figure 7). Furthermore, a metal rod 71 is embedded in each of both sides of the rigid member 7. The metal rod 71 extends horizontally from the center of the rigid member 7 outward on both the left and right sides. The rigid member 7 has higher rigidity against load input in the front-to-rear direction than the main body 6. Furthermore, no metal rod is embedded in the center of the rigid member 7. The center of the rigid member 7 has relatively low rigidity, while the both sides have relatively high rigidity.

[0061] The rigid member 7 extends in the left-right direction near the upper end of the main body 6. When viewed from the front, the rigid member 7 overlaps with the fixing portion 68 and the first side piece 61 of the main body 6. The rigid member 7 is fixed to the main body 6 at a central portion where rigidity is relatively low. The rigid member 7 extends outward on both the left and right sides beyond the tip of the first side piece 61.

[0062] The frame 2 supports the pressure-receiving member 4. The connecting member 8 connects the frame 2 and the pressure-receiving member 4 together.

[0063] The connecting member 8 includes an upper connecting member 81 and a lower connecting member 82. The upper connecting member 81 connects the rigid member 7 to the frame 2. The lower connecting member 82 connects the lower end of the main body 6 to the frame 2.

[0064] The upper connecting member 81 includes a first upper connecting member 811 on the right side and a second upper connecting member 812 on the left side. The first upper connecting member 811 and the second upper connecting member 812 have shapes that are symmetrical with respect to the center line of the seat back 11. In the following, the structure of the first upper connecting member 811 will be described in detail, and a description of the structure of the second upper connecting member 812 will be omitted as appropriate.

[0065] The first upper connecting member 811 connects the rigid member 7 to the right part of the upper frame 22. The connection position between the first upper connecting member 811 and the rigid member 7 is the right part of the center of the rigid member 7. More specifically, the connection position between the first upper connecting member 811 and the rigid member 7 is outside in the left-right direction of the fixed position between the rigid member 7 and the main body 6 (see the right diagram in FIG. 5 or FIG. 6). As shown in FIG. 7, the first upper connecting member 811 is located at a position overlapping in the left-right direction with the metal rod 71 embedded in the rigid member 7.

[0066] The first upper connecting member 811 extends directly upward from the connection position with the rigid member 7, and then bends diagonally upward to the right at a first bent portion 813. The first upper connecting member 811 then bends directly upward at a second bent portion 814, and then reaches the right side of the upper frame 22. Similarly, the second upper connecting member 812 extends directly upward from the connection position with the rigid member 7, and then bends diagonally upward to the left at a first bent portion 815, and then bends directly upward at a second bent portion 816, and then reaches the left side of the upper frame 22.

[0067] The first upper connecting member 811 and the second upper connecting member 812 are small-diameter rod-shaped members made of metal. The rigid member 7 and the first upper connecting member 811 and the second upper connecting member 812 are integrally formed by, for example, insert molding.

[0068] The lower connecting member 82 includes a first lower connecting member 821 on the right side and a second lower connecting member 822 on the left side. The first lower connecting member 821 and the second lower connecting member 822 on the left side have shapes that are symmetrical with respect to the center line of the seat back 11. In the following, the structure of the first lower connecting member 821 will be described in detail, and a description of the structure of the second lower connecting member 822 will be omitted as appropriate.

[0069] The first lower connecting member 821 connects the lower end of the base 69 to the right part of the lower frame 23. The first lower connecting member 821 and the base 69 are connected to the right part of the base 69.

[0070] The first lower connecting member 821 protrudes outward to the right from the right side of the base 69, and then curves in a U-shape. As shown in Fig. 2, the first lower connecting member 821 is attached to a first attachment portion 231 provided on the right side of the lower frame 23. Similarly, the second lower connecting member 822 protrudes outward to the left from the left side of the base 69, and then curves in a U-shape and is attached to a second attachment portion 232 provided on the left side of the lower frame 23.

[0071] The first lower connecting member 821 and the second lower connecting member 822 are also small-diameter rod-shaped members made of metal. The base 69 and the first lower connecting member 821 and the second lower connecting member 822 are integrally formed by, for example, insert molding.

[0072] The pressure-receiving member 4 is fixed to the frame 2 by a pair of upper connecting members 81 and a pair of lower connecting members 82. When the pressure-receiving member 4 receives an impact load from the back of the occupant 9 during a rear-end collision of the vehicle, for example, the pressure-receiving member 4 can be displaced rearward due to elastic deformation of the pair of upper connecting members 81 and the pair of lower connecting members 82. The displacement of the pressure-receiving member 4 reduces the impact load acting on the neck of the occupant 9 during the collision.

[0073] As described above, the upper connecting member 81 may be a single member formed by connecting the lower ends of the first upper connecting member 811 and the second upper connecting member 812 together, instead of including a pair of connecting members, the first upper connecting member 811 and the second upper connecting member 812. Similarly, the lower connecting member 82 may be a single member formed by connecting the left and right first lower connecting members 821 and the second lower connecting members 822 together, instead of including a pair of connecting members, the first lower connecting member 821 and the second lower connecting member 822.

[0074] As shown in FIG. 4 or the right diagram of FIG. 6, an intermediate connecting member 83 is located on the rear side of the base 69. The intermediate connecting member 83 connects the rigid member 7 to the lower end of the base 69. The intermediate connecting member 83 includes a first intermediate connecting member 831 on the right side and a second intermediate connecting member 832 on the left side. The first intermediate connecting member 831 and the second intermediate connecting member 832 have shapes that are symmetrical with respect to the center line of the seat back 11. In the following, the structure of the first intermediate connecting member 831 will be described in detail, and a description of the structure of the second intermediate connecting member 832 will be omitted as appropriate.

[0075] The upper end of the first intermediate connecting member 831 is fixed to the rigid member 7. The fixed position of the first intermediate connecting member 831 in the left-right direction is the same as the fixed position of the first upper connecting member 811. The first intermediate connecting member 831 extends straight down from the rigid member 7 and then bends diagonally downward to the right. The first intermediate connecting member 831 then bends straight down again and reaches a third mounting portion 691 provided at the lower end of the base 69. The third mounting portion 691 and the first mounting portion 231 are located at approximately the same position in the left-right direction. The second intermediate connecting member 832 extends straight down from the rigid member 7 and then bends diagonally downward to the left, then bends straight down again and reaches a fourth mounting portion 692 provided at the lower end of the base 69. The fourth mounting portion 692 and the second mounting portion 232 are located at approximately the same position in the left-right direction.

[0076] The intermediate connecting member 83 increases the rigidity of the pressure-receiving member 4 including the base portion 69 and the rigid member 7 , and also supports the lumbar support 40 .

[0077] The lumbar support 40 is located behind the pressure-receiving member 4 and supports the lumbar region of the occupant 9 via the pressure-receiving member 4. The lumbar support 40 is generally V-shaped when viewed from behind. The right and left sides of the lumbar support 40 are engaged with the first intermediate connecting member 831 and the second intermediate connecting member 832, respectively. The position of the lumbar support 40 can be changed in the up and down direction along the first intermediate connecting member 831 and the second intermediate connecting member 832. The lumbar support 40 can appropriately support the lumbar region of the occupant 9 by changing its position according to the physique of the occupant 9. As shown in FIG. 6 , the lumbar support 40 moves up and down between an upper limit UL and a lower limit LL. The upper limit UL is the position where the lumbar support 40 and the rigid member 7 interfere with each other. The lower limit LL is the position where the first intermediate connecting member 831 and the second intermediate connecting member 832 bend. The fixing portion 68 bulges upward to position the upper limit UL at a higher position. The fixing portion 68 increases the range in which the lumbar support 40 can be raised and lowered.

[0078] A gear box 41 including an electric motor is located below the lumbar support 40. The electric motor is a drive source for raising and lowering the lumbar support 40. The gear box 41 has a worm gear 42. The worm gear 42 extends directly upward from the gear box 41. The upper end of the worm gear 42 is fixed to the center of the lower end of the lumbar support 40. When the electric motor rotates, the lumbar support 40 rises and falls together with the worm gear 42. The occupant can raise and lower the lumbar support 40 by operating a switch.

[0079] (Seatback structure that supports the occupant's back while reducing discomfort to the occupant) As described above, the pressure-receiving member 4 is attached to the frame 2 via the connecting member 8. The pressure-receiving member 4 receives the load from the back of the occupant 9 and supports the back of the occupant 9.

[0080] The pressure-receiving member 4 has a main body 6 and a rigid member 7. The rigid member 7 is fixed to the rear side of the main body 6 at a position corresponding to the thorax 91 of the occupant 9. The rigid member 7 also extends in the width direction of the seat back 11 and is connected to the frame 2 by connecting members 8 at multiple points at different positions in the width direction. Because the main body 6 is connected to the frame 2 via the rigid members 7, the pressure-receiving member 4 can firmly support the back of the occupant 9. For example, in the event of a rear-end collision of the vehicle, the pressure-receiving member 4 can support the back of the occupant 9 that receives the impact load. As described above, in the event of a rear-end collision, the pressure-receiving member 4 can move rearward due to elastic deformation of the connecting members 8.

[0081] On the other hand, when the vehicle is normally running, the load from the back of the occupant 9 is received by the main body 6 of the pressure-receiving member 4, which has a relatively low rigidity. The reaction force on the back of the occupant 9 is prevented from becoming too strong, and the discomfort felt by the occupant 9 is reduced.

[0082] Therefore, the vehicle seat back 11 can reliably support the back of the occupant 9 while reducing the discomfort felt by the occupant 9.

[0083] Furthermore, in the main body 6 having a base 69 and side pieces 60, the central part of the main body 6, i.e., the base 69, has relatively high rigidity, while both side parts, i.e., the side pieces 60, have relatively low rigidity. The connection point between the rigid member 7 and the connecting member 8 is on the central side corresponding to the position of the base 69, and the rigid member 7 is fixed to the base 69 on the central side of the connection point between the rigid member 7 and the connecting member 8. This allows the pressure-receiving member 4 to firmly support the central side of the back of the occupant 9 when the vehicle is normally running.

[0084] Furthermore, because the rigid member 7 extends long in the width direction, it is possible to distribute the load from the occupant 9 input through the main body 6. This also enables the pressure-receiving member 4 to firmly support the back of the occupant 9.

[0085] Due to the metal rods 71 ​​embedded therein, both side portions of the rigid member 7 have relatively high rigidity, while the central portion has relatively low rigidity. The load from the back of the occupant 9 is input to the central portion of the rigid member 7, which has relatively low rigidity. Because the rigidity of the rigid member 7 differs in the longitudinal direction, the central portion and both side portions of the rigid member 7 are displaced in opposite directions when a load is input. In other words, when the central portion is displaced rearward, the both side portions are displaced forward, and when the central portion is displaced forward, the both side portions are displaced rearward, thereby allowing the rigid member 7 to withstand the load. The pressure-receiving member 4 can firmly support the back of the occupant 9.

[0086] Furthermore, since the fixing portion 68 of the base portion 69 is located above the position of the side piece 60, the rigid member 7 fixed to the upper end portion of the main body 6 can firmly support the pressure-receiving member 4.

[0087] (Seatback structure that suppresses changes in occupant posture when cornering without compromising ride comfort) As shown in Fig. 8, the pad 3 has a reinforcement reduced portion 321. The reinforcement reduced portion 321 reduces the reinforcement of the reinforcing member 32 attached to the rear surface of the foam member 31. The reinforcement reduced portion 321 in Fig. 8 is a notch formed in the reinforcing member 32.

[0088] As shown in Fig. 2, the reinforcing lowered portions 321 are located at positions overlapping with the first side pieces 61 on both the left and right sides when viewed from a direction perpendicular to the surface of the seat back 11. These positions correspond to the lower parts of the thorax 91 of the occupant 9 as shown in Fig. 5. The two reinforcing lowered portions 321 are located symmetrically with respect to the center line of the seat back 11.

[0089] In the illustrated example, the reinforcing lowered portion 321 has a substantially quarter-circular shape when viewed from the rear. However, the shape of the reinforcing lowered portion 321 is not limited to the illustrated example. The reinforcing lowered portion 321 may have a polygonal, circular, or elliptical shape when viewed from the rear.

[0090] As described above, the base 69 of the main body 6 of the pressure-receiving member 4 is located at the center in the width direction of the seat back 11 and supports the center of the back of the occupant 9. The side pieces 61 to 67 are located on both sides of the base 69 and support both sides of the back of the occupant 9, respectively.

[0091] When the vehicle is traveling straight, the pressure-receiving member 4 receives the load from the entire back of the occupant 9 via the pad 3. As described above, the pad 3 has the foam member 31 and the reinforcing member 32. The load from the back of the occupant 9 is received mainly by the base 69 of the pressure-receiving member 4 while the foam member 31 reinforced by the reinforcing member 32 undergoes compressive deformation. The pad 3 and the pressure-receiving member 4 receive the load from the back of the occupant 9 over their entire wide surfaces. Therefore, when the vehicle is traveling straight, the seat back 11 can firmly support the back of the occupant 9 without applying a strong reaction force to the back of the occupant and without deteriorating the ride comfort.

[0092] When the vehicle turns, the posture of the occupant 9, that is, the driver or passenger, tends to change in a direction in which the thorax 91 rotates around the spine and / or in a direction in which the thorax 91 tilts to the left or right. As the posture of the occupant 9 changes, a load is locally input to the seat back 11 from the side of the back of the occupant 9.

[0093] A local load from the side of the back of the occupant 9 is input to the pad 3 at the position of the reinforcement lowering portion 321 corresponding to the thorax 91. At the initial stage of input of the local load, the foam member 3 undergoes large compressive deformation at the reinforcement lowering portion 321. This prevents a strong reaction force from acting on the occupant 9 at the initial stage of input of the local load.

[0094] After the foam member 31 is compressed and deformed, the local load from the side of the back of the occupant 9 is received mainly by the first side piece 61 of the pressure-receiving member 4. Then, a reaction force acts on the side of the back of the occupant 9 from the pressure-receiving member 4 through the pad 3. This suppresses changes in the posture of the occupant 9.

[0095] Therefore, when the vehicle turns, the seat back 11 can firmly support the back of the occupant 9 and suppress changes in posture while suppressing a strong reaction force on the occupant 9.

[0096] On the other hand, the reinforcing lowered portion 321 is provided partially at a specific location on the pad 3. When a load is input to the seat back 11 from the entire back of the occupant 9, such as when the vehicle is traveling straight, the reinforcing lowered portion 321 does not substantially function. The seat back 11 does not deteriorate the riding comfort when the vehicle is traveling straight.

[0097] Therefore, the seat back 11 can suppress changes in the posture of the occupant 9 when turning without deteriorating the riding comfort when traveling straight or turning.

[0098] Furthermore, the reinforcing lowering portions 321 are located on both sides of the center line of the seat back 11 in the width direction. That is, the reinforcing lowering portions 321 are located on both the right and left sides of the back of the occupant 9. When turning right and left, the seat back 11 can suppress changes in the posture of the occupant 9.

[0099] Furthermore, the first side piece 61, which overlaps with the reinforcing lowered portion 321, has higher rigidity than the second side piece 62. The highly rigid first side piece 61 can apply a sufficient reaction force to the side of the back of the occupant 9. As a result, changes in the posture of the occupant 9 can be suppressed when the vehicle turns.

[0100] Furthermore, since the reinforcement lowering portion 321 is located behind the thorax 91 of the occupant 9, the first side piece 61 of the pressure-receiving member 4 can apply a reaction force to the thorax 91 that tends to displace when the vehicle turns. The seat back 11 can effectively suppress changes in the posture of the occupant 9.

[0101] Since each of the side pieces 61 to 67 extends forward and outward in the width direction from the base 69, the first side piece 61 can apply a reaction force to the area extending from the side of the back of the occupant 9 to the side of the body of the occupant 9. The seat back 11 can effectively suppress changes in the posture of the occupant 9 in the direction in which the thorax 91 rotates and / or in the direction in which the thorax 91 tilts left or right.

[0102] Furthermore, the nonwoven fabric serving as the reinforcing member 32 controls the compression amount of the foam member 31, so that the vehicle seat back 11 appropriately supports the back of the occupant 9 and improves riding comfort. The notches serving as the reinforcing lowering portions 321 formed in the nonwoven fabric do not constrain the rear surface of the foam member 31, and therefore reduce the reaction force when a local load is input from the back of the occupant 9. As a result, as described above, the reinforcing lowering portions 321 initially reduce the reaction force on the back of the occupant 9 in response to the local load input when the vehicle turns, and thereafter, the first side piece 61 of the pressure-receiving member 4, mainly, can apply a sufficient reaction force to the back of the occupant 9, thereby suppressing changes in the posture of the occupant 9.

[0103] The reinforcing lowering portion 321 is not limited to a cutout, and may be a slit formed in the reinforcing member 32, as shown in FIG. 9. While the slit in FIG. 9 is a sideways U-shape, the slit may be, for example, an L-shape. Like the cutout, the slit also releases the constraint on the rear surface of the foam member 31 by the reinforcing member 32. Therefore, as described above, in response to a local load input when the vehicle turns, the reaction force on the back of the occupant 9 is initially reduced, and thereafter, a sufficient reaction force can be applied to the back of the occupant 9 mainly by the side pieces 60 of the pressure-receiving member 4, thereby suppressing changes in the posture of the occupant 9. [Explanation of symbols]

[0104] 1. Vehicle seat back 2 Frame (seat back frame) 3 Pad 31 Foam materials 32 Reinforcement member 321 Reinforced lowering section 4 Pressure-receiving member 51 Airbag 6 Main unit 60 side pieces 61 1st side piece (specific side piece) 68 Fixed part 69 Base 7 Rigid members 8 Connecting members 9 crew members 91 Thoracic Cage

Claims

1. A pad that supports the back of the occupant, a pressure-receiving member located behind the pad and receiving a load from the back of the occupant via the pad, The pad includes an elastically deformable foam member and a reinforcing member attached to a rear surface of the foam member and reinforcing the foam member, The pressure-receiving member has a base portion located at a center portion in a width direction of the seat back, and a plurality of side pieces extending outward in the width direction from both sides of the base portion, The pad has a reinforcement reducing portion that reduces the reinforcement of the reinforcing member at a position that overlaps with a part of the side piece when viewed from a direction perpendicular to the surface of the seat back.

2. The vehicle seat back according to claim 1, The vehicle seat back, wherein the reinforcing lowered portions are located on both sides of the center line of the seat back in the width direction.

3. The vehicle seat back according to claim 1 or 2, The side pieces are arranged at intervals in the up-down direction on both sides of the base, The reinforcing lowered portion overlaps with the specific side piece on each side of the base portion, The specific side piece has higher rigidity than the side piece adjacent to the specific side piece.

4. The vehicle seat back according to any one of claims 1 to 3, The vehicle seat back, wherein the reinforcement lowering portion is positioned behind the thorax of the occupant.

5. The vehicle seat back according to any one of claims 1 to 4, The side pieces extend forward and outward in the width direction from the base portion.

6. The vehicle seat back according to any one of claims 1 to 5, the reinforcing member is a nonwoven fabric, The vehicle seat back, wherein the reinforcing lowered portion is a notch or a slit formed in the nonwoven fabric.

7. The vehicle seat back according to any one of claims 1 to 6, The vehicle seat back further comprises an airbag for seat ventilation positioned between the pad and the pressure-receiving member.

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